IT’S 100 YEARS ago, you’re in Fairfax and you just read about the fabulous Sutro Baths. “The Largest Indoor Swimming Palace in the World,” says the advertisement, “with six saltwater pools of varying temperatures, plus one freshwater pool and numerous waterslides and springy diving boards.” So without the Golden Gate Bridge, how did folks from far-flung Fairfax get to Ocean Beach? “You’d catch a 12:24 p.m. Northwestern Pacific Railroad electric interurban train from downtown Fairfax,” says rail historian Fred Codoni about his hometown. “It cost maybe 20 cents and arrived in Sausalito at 12:55 p.m.” Then came a ferry to San Francisco, leaving at 1 p.m. and reaching the Ferry Building by 1:35 p.m. “From there you took a Market Street Railway trolley,” Codoni says, “and the seven-mile ride cost ten cents and took about one hour.” The Sutro Baths cost San Francisco Mayor Adolph Sutro $1 million to build. It opened in 1896 and remained an Ocean Beach landmark until 1966, when it was consumed in a spectacular fire during its demolition.